%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 5-12-11 on page 273.
%% 
%%  Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert Vo\ss 
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.83385pt}
\StartShownPreambleCommands
\usepackage{pstricks}
\usepackage{pst-node}
\StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-0.25,-0.25)(3.25,0.5)
  \psset{nodesep=3pt,shortput=nab}
  \cnode(0,0){0.5cm}{A}\rput(0,0){$x_1$}
  \cnode(3,0){0.5cm}{B}\rput(3,0){$x_{n-1}$}
  \ncarc[arcangle=40]{->}{A}{B}^{$c(x_{n-1})$}
\end{pspicture}
\end{document}